OCC wrong fillet type

Hello from Germany,
I'm a Freecad user and active https://forum.freecadweb.org member.
Many times users reported errors concerning fillets. Freecad developer and me figured out that OCC uses a different fillet type than PTC Creo, Solidworks, Catia and others. Best to see in this picture with a variable radius:
First picture Freecad variable radius:
https://forum.freecadweb.org/download/file.php?id=30843
Second picture Pro-Engineer Wildfire 5.0:
https://forum.freecadweb.org/download/file.php?id=30866

Please have a look at this problem, It's a sphere radius 25mm with a hole radius 15mm , like to see in this picture:
https://forum.freecadweb.org/download/file.php?id=42364
It's impossible to create a fillet creater than 0,05mm.

With a half sphere it's possible to create the fillets, but they are totaly different and wrong compared to ProE:
https://forum.freecadweb.org/download/file.php?id=42366
Red is ProE, grey Freecad, fillet is radius 8mm.
You can find the forum discussion with freecad files here:
https://forum.freecadweb.org/viewtopic.php?p=187904#p187904

Please help to fix this error.

Thank you so much and best regards from Germany

Herbert